CyberHunter
// Voice & chat

Port 1718: H.323 Multicast Gatekeeper Discover

Port 1718 is assigned by IANA to h323gatedisc (H.323 Multicast Gatekeeper Discover).

1718

How h323gatedisc works

Voice & chat
callercalleeh323gatedisc callercalleeh323gatedisc

Port 1718 sets up the call (who calls whom), then the voice travels as a stream of audio packets.

Transport
TCP · UDP
Exposure risk
not rated depends on the program listening
Encryption
Unknownnot stated by the registry
IANA status
Assigned1 registered service
Range
Registered (1024-49151)
Category
Voice & chat
01 Security

Is port 1718 dangerous?

We have no specific security note for port 1718. Its risk depends on the program actually listening on it. General advice for voice & chat services:

  • Use strong credentials and TLS for signalling.
  • Rate-limit registrations to stop extension scanning and toll fraud.
  • Alert on unexpected chat protocols leaving servers (possible command and control).
02 Registry

IANA registry entries for port 1718

ServicePortTransportDescriptionReferenceUpdated
h323gatedisc 1718 TCP, UDP H.323 Multicast Gatekeeper Discover - 2013-01-31

// source: IANA service name and port number registry

03 Check it

Which program uses port 1718, and is it reachable?

Linux

sudo ss -ltnup 'sport = :1718'      # process listening on 1718
sudo lsof -nP -i :1718

macOS

sudo lsof -nP -i :1718

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 1718 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 1718
netstat -ano | findstr :1718

From another machine

nmap -p 1718 -sV <host>
sudo nmap -sU -p 1718 <host>
nc -zv <host> 1718

Block it in the firewall

sudo ufw deny 1718/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 1718" -Direction Inbound -LocalPort 1718 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 1718 used for?

Port 1718 is assigned by IANA to h323gatedisc (H.323 Multicast Gatekeeper Discover).

Is port 1718 TCP or UDP?

Port 1718 is registered for TCP and UDP.

Is it safe to open port 1718?

It depends on the program that listens on it. Open it only for a service you know and only to the networks that need it. Use strong credentials and TLS for signalling.

How do I check if port 1718 is open?

On Linux run "ss -ltnup 'sport = :1718'", on macOS "lsof -nP -i :1718", and on Windows "netstat -ano | findstr :1718" to see the local process. From another machine, "nmap -p 1718 <host>" shows whether it is reachable.

05 Related